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On a 100 km straight road, a car travels the first half at auniform speed of 30 km h'. How fast must the car travelfor the next half so that the average speed of 45 km hisattained for the journey? |
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Answer» in first half d=50km s=30kmph TIME=(50/30)hr=1.66hr Explanation: total DIST =100km and ave speed =45kmph=(total dist)/(total time) =100/t so t=100/45 =2.22hr which means second LEG of 50km was DONE in 2.22-1.66 =0.56 hr so speed was 50/0.56 =89.28 kmph ANSWER |
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